Science:Math Exam Resources/Courses/MATH152/April 2017/Question A 02/Solution 1

We compute the product by distributing:
$\begin{aligned} u z & = (1 + 3 i) (2 - i) \\ = 2 - i + 6 i - 3 i^{2} \\ = 2 + 5 i + 3 \\ = 5 + 5 i . \end{aligned}$
Answer: $u z = 5 + 5 i$